The present invention generally relates to an apparatus for controlling the burn-off operation of a gas in a furnace used for fabricating semiconductor wafers and, more particularly, is concerned with an apparatus and method for controlling the current supplied to the ignitors and monitoring the temperature of the ignitors during the burn-off operation of hydrogen gas in the furnace. Known systems for such burn-off operations have a high failure rate and are complex and expensive. In one known system, a voltage sensor is used for monitoring the current of the ignitor which is not reliable. In addition, known systems do not provide a display of the burn-off temperature, thereby making it difficult to monitor the gas burn-off temperature for the purpose of trouble-shooting when a failure occurs.